New phone on AT&T Website

I just recently got a iPhone 3Gs (paid outright not a upgrade), My current phone is the Blackberry Bold 9700 with a unlimited data plane. I downloaded the APN app to my iPhone and changed everything over so that it would work on the BB data plan. But i noticed when i went to AT&T website my phone was changed to the iPhone while i was using that and then went back to my BB when I was using it. Will this cause any problems? Did I change it correctly? my iPhone connected to the web with no problems while i had my Sim card in it.